Psychiatric disorders are common in neurologic disorders, and often occur as a consequence of neurologic disorders. Prompt diagnosis and treatment can improve outcomes, so neurologists should be familiar with typical manifestations and treatments. Depression, apathy, anxiety disorders, PTSD, psychosis, and conversion disorder are common psychiatric conditions encountered by neurologists. All patients should be screened for psychiatric disorders. Neurologists should always evaluate for suicidality and risk of violence to others in patients with psychiatric symptoms. A multimodal biopsychosocial treatment approach—involving medications, psychotherapy, and psychoeducation—is often the most helpful strategy.

Why should neurologists familiarize themselves with the diagnosis and management of psychiatric illnesses?

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  Psychiatric symptoms can occur idiopathically, or as a consequence of a neurologic disorder.¹ At times, psychiatric symptoms may represent the initial presentation of an underlying neurologic illness.

  
  
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  Psychiatric disorders are common but underdiagnosed, in both the general population and in patients with neurologic diseases.

  
  
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  Psychiatric symptoms cause immense personal suffering and worsen neurologic outcomes.

  
  
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  Most psychiatric illnesses respond to treatment, which improves both psychiatric and neurologic outcomes.

  
  
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  Neurologists need to distinguish between idiopathic psychiatric disorders and psychiatric symptoms due to neurologic disorders or general medical conditions—if they do not, the underlying condition may remain undiagnosed and untreated, and the patient may worsen, when management focuses only on the psychiatric symptoms.

  
  
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  When psychiatric disorders occur due to a neurologic disorder, they do not necessarily exactly resemble the idiopathic forms described in Diagnostic and Statistical Manual, Fifth Edition (DSM 5), the standard reference criteria used by psychiatrists.

Which neurologic disorders are most likely to be accompanied by psychiatric symptoms?

Neurologic disorders with prominent psychiatric manifestations include:¹

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  Stroke

  
  
  
  
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    Poststroke depression, apathy, post-traumatic stress disorder (PTSD), and anxiety disorders each occur in about one fourth to one third of stroke survivors (some patients have more than one of these conditions)^2,3

  
  
  
  
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  Epilepsy

  
  
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  Dementia

  
  
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  Movement disorders (especially Parkinson disease and Huntington disease)

  
  
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  Limbic encephalitis

  
  
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  Multiple sclerosis

Can general medical conditions produce both neurologic and psychiatric symptoms?

Yes. Examples include:^4–6

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  Endocrinopathies, such as thyroid disorders (even “subclinical” thyroid disorders)

  
  
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  Vitamin deficiencies, such as B12, folate, and vitamin D deficiency

  
  
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  Toxic exposures, such as heavy metal poisoning

  
  
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  Autoimmune disorders, such as systemic lupus erythematosus

  
  
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  Paraneoplastic syndromes

  
  
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  Infections, such as HIV and syphilis

  
  
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  Medication/drug use or withdrawal

Laboratory tests to routinely check on patients with psychiatric symptoms include TSH, FT4, CBC, B12, folate, Vitamin D, HIV, syphilis serology, and urine drug screen.⁷

Can the medications used to treat neurologic disorders cause, worsen, or improve psychiatric symptoms?

Yes. Many commonly used neurologic medications have potential psychiatric effects—both helpful and harmful (Table 49-1).

What conditions may mimic psychiatric disorders in patients with neurologic illnesses?

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  Patients with delirium may appear manic, depressed, anxious, or psychotic. However, the fluctuating level of consciousness seen in delirium distinguishes it from other psychiatric disorders.⁸

  
  
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  Patients with a serious neurologic disorder can experience low mood or anxiety as a normal human reaction to illness; these reactions should not rise to the level of severity or pervasiveness that characterizes a psychiatric disorder.⁹

Diagnosis

How are psychiatric disorders diagnosed?

A thorough history remains the basis for most psychiatric diagnoses.⁷ Neurologists who know the characteristic signs and symptoms of psychiatric disorders can query their patients about their presence or absence. Structured questionnaires can also help detect psychiatric disorders.⁷

In addition to interviewing the patient, talk to his or her family and friends, as many patients have poor insight into their psychiatric symptoms.⁷ When clinicians work cross-culturally, collateral informants who share the patient’s background can clarify whether symptoms represent normal phenomena for their culture.

Should neurologists assess whether patients pose a safety risk to themselves or others?

Yes. All clinicians should assess for the presence of suicidality and homicidality in every patient with psychiatric symptoms or other disorders potentially associated with safety risks. Almost half of patients who commit suicide saw a nonpsychiatrist physician within one month of their death; assessing safety is every clinician’s responsibility.¹⁰ Patients with stroke have a 7% chance of ultimately dying by suicide; other neurologic illnesses, including epilepsy and multiple sclerosis, also show a higher suicide risk than the general population.^11,12

How can clinicians assess safety?

The key to assessing whether a patient may be suicidal or homicidal is to ask the patient specifically.¹³ Making assumptions about who could be dangerous (based on demographics, patient interactions, or gut feelings) can result in overlooking patients with these thoughts and missing an opportunity to intervene and save a life (Figure 49-1).

Similar questions about thoughts/plans of harming others can help evaluate the presence of homicidal ideation.

What else should clinicians ask about when assessing for violence?

Other risk factors for suicide to ask about include:¹³

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  Family history of suicide or suicide attempts

  
  
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  Gun ownership/access (use of a firearm is much more likely to result in death than other means of suicide)

  
  
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  Substance use (intoxication is a suicide risk factor)

  
  
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  Tendency toward impulsiveness

  
  
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  Severe anxiety, panic attacks, or hopelessness

Other risk factors for violence to others to ask about include:¹⁴

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  History of violent behavior (Ask: “What’s the most violent thing you have ever done?”)

  
  
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  Substance use

  
  
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  Ownership of/access to guns and other weapons

  
  
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  Tendency toward impulsiveness

Should clinicians also consult collateral sources when evaluating for safety risk?

Yes. Interview family/friends and consult past medical records, as they may provide additional history about violence risk that the patient did not disclose.¹³ If the family or friends have concern about the safety of the patient or others—even if the patient denies suicidal or homicidal ideation—then the physician needs to embark on further assessment or action.

How should a neurologist respond when there are concerns for suicidality or homicidality?

First, ensure safety.¹³ Do not let the patient leave if you are concerned about an imminent risk of harm to self or others; do not leave the patient unsupervised if you are concerned he or she may act on these thoughts while in the hospital. While the specifics of involuntary holds vary, almost every jurisdiction has a procedure for detaining patients who may endanger self or others. In the case of threats to others, you may also have an obligation or an option to inform law enforcement and the patient’s potential victims, again depending on local laws.

When dealing with a potentially suicidal or homicidal patient, obtain urgent psychiatric consult if possible, to facilitate further assessment, treatment, and transfer.

If after thorough assessment, it appears that a patient with suicidal or homicidal ideation does not pose a safety threat, safety planning still remains essential.¹³

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  Discuss with the patient (and family/friends if possible) about what to do if the thoughts of violence intensify. Depending on severity, this could entail contacting the care provider, going to the ER, or calling 911.

  
  
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  Remove access to guns, if the patient has any. This could involve getting rid of the guns, temporarily storing them in someone else’s house, or at minimum, locking them in a safe and making sure the patient does not have access to the key.

  
  
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  Remove other lethal means of suicide/violence: for instance, have a relative keep the patient’s medication and only give the patient enough doses for one day or one week, to limit the possibility of overdose.

Of course, treat the underlying psychiatric illness causing the suicidality or homicidality.

Treatment

What treatment approaches are most helpful for patients with psychiatric disorders?

The majority of patients benefit most from a biopsychosocial treatment approach combining somatic treatments, psychotherapy, and optimization of interpersonal relationships and social support. While many patients require inpatient psychiatric consultation and/or outpatient psychiatry follow-up, neurologists can provide important interventions such as:

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  Initiating psychotropic medications. Many agents, particularly antidepressants, can take several weeks to begin to work; the sooner the patient starts on medication, the sooner he or she can recover.

  
  
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  Encouraging the patient to participate in psychotherapy, by providing education about what psychotherapy involves and how it will help.

  
  
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  Assisting the patient in marshalling social support resources.

  
  
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  Referring for follow-up care.

What are some general principles of psychotropic medication management in neurology patients?

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  Start at the lowest effective dose and titrate slowly, as neurology patients may experience more side effects.¹⁵

  
  
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  Allow an adequate trial before declaring a medication failure. The trial should extend for an adequate duration (in the case of antidepressants, at least 6–12 weeks at each dose). The dose should be titrated up until symptoms resolve, the highest approved dose is reached, or side effects develop.¹⁵

  
  
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  Avoid benzodiazepines and most sedative-hypnotics (trazodone may represent an exception). In addition to worsening cognition and potentially precipitating delirium during the period of use, benzodiazepines are associated with increased risk for new-onset dementia,¹⁶ and both benzodiazepines and sedative-hypnotics (other than trazodone) are associated with increased all-cause mortality.¹⁷ Benzodiazepines also carry dependence liability and increase the risk of falls.¹⁸ If patients already take a benzodiazepine, try to taper them off. Cognitive-behavior therapy for insomnia (CBT-I) represents the most effective long-term treatment for insomnia.¹⁹

  
  
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  Avoid polypharmacy of CNS-active medications if possible, particularly in elderly patients and patients with cognitive impairment.¹⁸

What types of psychotherapy are most effective?

In general, the different types of psychotherapy show equal efficacy; however, just as with medications, a specific type may be most appropriate for a specific patient. For example, a patient with mild cognitive impairment will likely benefit more from supportive psychotherapy, which focuses on maximizing the use of the patient’s available psychological and social resources, rather than a more cognitively demanding therapy such as cognitive-behavioral therapy (CBT) or psychoanalysis.

The relationship between the patient and the therapist constitutes the most significant factor in determining the success of the therapy. If after a few sessions, the patient feels that the therapist is not the right one, he or she should switch to another therapist. It helps to explain to patients that therapists are professionals who will not take offense if someone leaves their care.

How can neurologists educate patients about psychotherapy and encourage them to participate?

Depression

What is depression?

A major depressive episode consists of low mood, anhedonia, and/or loss of interest in activities, accompanied by somatic, cognitive, and other psychological symptoms; symptoms last for 2 weeks or longer.⁵ In some individuals, depression manifests primarily with irritability. Patients do not have to show all of these symptoms to have a clinically significant depression (Figure 49-2).

Depression is more than just the low mood or sadness we all experience at times; depression must last for a sustained period and cause impairment in functioning.⁵

Poststroke depression can show up within days of a stroke, and the evidence suggests that prompt treatment at the onset of symptoms improves outcomes. Rather than waiting for 2 weeks to see if symptoms spontaneously resolve, neurologists should strongly consider treating poststroke depression as soon as it develops.

Major depression can occur idiopathically, or due to a neurologic disorder or other general medical condition.⁵ A major depressive episode can occur as part of a unipolar depression or as part of bipolar disorder; the treatment of bipolar depression differs substantially from unipolar depression. This chapter focuses exclusively on unipolar major depression.

Depression is a major risk factor for suicide.¹³Always ask patients with suspected depression about suicidal ideation.

How can neurologists evaluate patients for depression?

Patients may spontaneously report depressive symptoms, or exhibit behavior suggesting depression, such as crying. However, depression often goes overlooked if clinicians do not specifically ask about it. Given the high comorbidity between depression and neurologic disorders, neurologists should screen all patients.

In addition to asking about depressive symptoms during the clinical interview, using standardized screening instruments may help improve detection. The Patient Health Questionnaire-2 (PHQ-2) is a free, public-domain two-question screening test for depression, which clinicians can easily incorporate into their practice (Figure 49-3).²⁰

How is depression treated?

The goal of treatment is complete remission, not just symptom improvement. Residual subsyndromal symptoms contribute to personal suffering and cognitive impairment, and increase the risk of full-blown relapse.¹⁵

Combined medication treatment and psychotherapy offers the highest rate of successful treatment of depression.¹⁵ If a patient does not want to or cannot access both types of treatment, either medications alone or psychotherapy alone is also effective. Some studies indicate that for mild depression, psychotherapy should be the first-line treatment.¹⁵